Background: Gestational trophoblastic neoplasia (GTN) originates from placental trophoblast and is a highly chemosensitive and curable gynecologic malignancy. The present study was conducted to evaluate the effectiveness and safety of EMA/EP (etoposide, methotrexate, actinomycin-D, etoposide, and cisplatin) regimen in the treatment of high-risk GTN as well as patients’ outcome. Methods: Hospital charts of all patients with confirmed diagnosis of high-risk GTN who received EMA/EP regimen treatment during a 12-year period (2001-2012) at the tertiary center of comprehensive women's hospital in Tehran, Iran, were reviewed from 2012 to 2013, retrospectively. Results: In this study, 25 patients with GTN who were treated with EMA/EP regimen during the study were identified. Complete remission rate in GTN patients with failure of single agent chemotherapy who were treated with EMA/EP regimen, as the first- line treatment, was 100%, while it was 81% in those with primary high-risk GTN. Overall remission rate in high-risk GTN patients treated with EMA/EP regimen was 88%. Anemia (92%) and leucopenia (72%) were the most common adverse effects of EMA/EP chemotherapy regimen. Acute myeloid leukemia (AML) and mortality, as the most severe adverse effects of EMA/EP regimen, were seen only in 1 patient. Conclusion: According to the results, EMA/EP regimen could induce complete remission in 88% of patients with high-risk GTN. Application of EMA/EP is recommended as the first- line therapy in patients with failure of single agent chemotherapy. However, proper care should be considered to prevent and reduce EMA/EP hematologic toxicity.